Things were progressing fast and Sam knew that the situation could easily become desperate if they stalled any longer.
Sam knew Rachel didn't have the expertise for what they were about to do next and this was why he told Clementine to stay out with her so she could watch over her while also providing cover.
Sam dug and placed something at the entrance, this was a countermeasure to being caught off-guard, this thing buried was a grenade.
Sam was cautious, his concentration was at its max as a cold bead of sweat dripped down his forehead.
This wasn't fear but rather Sam's understanding of how dire this situation was, he knew that for killers to be tamed then there had to be some sort of force that could keep them contained.
"Hang in there, Jason," Sam said, for the first time showing genuine concern for the young man.